JP2006277974A - Battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery capable of suppressing an external short circuit not only in abnormality occurrence but also in the case of an unused state. <P>SOLUTION: This battery is characterized by that a sealing member 3 electrically connected to a positive electrode is not electrically connected to a battery cap 12 in an unused state of the battery by installing, between the battery cap 12 and the sealing member 3, a spring 15 for energizing both of them 3 and 12, and the battery cap 12 and the sealing member 3 are electrically connected to each other against the energizing force of the spring 15 in a used state of the battery. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a secondary battery such as a nickel-hydrogen battery, a nickel-cadmium battery, or a lithium ion battery, and more particularly to a battery having a structure in which a battery terminal also serves as an on / off switch for energization. .

  In recent years, with higher performance and miniaturization of electronic devices such as mobile phones, notebook personal computers, and PDAs, batteries used as drive power sources have been required to have higher energy density. As the energy density of such a battery increases, it is extremely important to ensure the safety of the battery.

  Conventionally, in order to ensure the safety of the battery, in a chemical battery having a power generation element, a positive or negative electrode terminal, and an outer can that also serves as another electrode terminal, the gas pressure or reaction heat generated when the battery is abnormal A method of blocking conduction between a partition plate sealing a battery container and an electrode terminal through an insulating material connected to an electrode by a driving member to be driven is known.

  In addition, as a battery safety protection device that cuts off the power generation element of a battery that has become an abnormal pressure, as shown in Patent Document 1 below, the sealing body body electrically connected to the electrode group is insulated from the sealing body body. A fixed metal terminal cap, a return type switch having a contact portion for electrical continuity from the sealing body to the terminal cap, and a non-reset type that is displaced outward as the pressure in the battery outer can rises. It has been proposed that an explosion-proof valve is provided, and the contact portion is pushed away by the outward displacement of the explosion-proof valve to cut off electrical conduction to the terminal cap.

Japanese Patent Laid-Open No. 9-320562

  However, in the above-described prior art, the safety device functions when an abnormality such as an increase in the battery internal pressure occurs when the battery is used. However, the operation of the safety device is not expected even when the occurrence of the abnormality is not predicted. When not in use, there is a possibility that another battery, a metal piece, or the like may be short-circuited by coming into contact with the battery, and when the short-circuit occurs, the battery may be deteriorated.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a battery that can suppress an external short circuit even when the battery is not used.

  In order to achieve the above object, the invention according to claim 1 of the present invention is such that a power generation element having positive and negative electrodes is housed in a bottomed cylindrical outer can, and this outer can is one of the positive and negative electrodes. A sealing body electrically connected to the other electrode of the positive and negative electrodes, and an opening of the outer can. A battery cap that is electrically connected to the other electrode terminal and is provided in order from the inside of the battery in an insulated state from the outer can, and when the battery is not used, The sealing member is not electrically connected, and the battery cap and the sealing member are electrically connected when the battery is used.

  With the above configuration, when the battery is used, the sealing body electrically connected to the other of the positive and negative electrodes and the battery cap are electrically connected to each other. At the time of use, since the sealing body and the battery cap are not electrically connected, the energization is disabled. Therefore, even when other batteries or metal pieces come into contact with the battery cap and the outer can when the battery is not used, it is possible to suppress external short-circuiting, and it is easy to use with excellent safety. A battery can be obtained.

  Moreover, since it is possible to suppress external short-circuiting during the transportation of the battery and the like, an insulating tube provided around the outer can is not necessary, and the manufacturing cost of the battery can be reduced. In addition, since the on / off switch is built in the battery, it is possible to reduce the number of parts of the power switch of the device in which the battery is used, thereby reducing the cost of the device.

  According to a second aspect of the present invention, in the first aspect of the present invention, a biasing means for biasing the battery cap and the sealing body in a direction to separate them is provided between the battery cap and the sealing body. The urging force is configured to be smaller than the urging force of the urging means provided in the device to which the battery is mounted.

  If the battery cap and the sealing body are provided with a biasing means for biasing the two in the direction of separating them as in the above configuration, the sealing body and the battery cap are electrically connected when the battery is not used. If the urging force of the urging means is smaller than the urging force of the urging means provided in the device to which the battery is attached, the battery cap and The sealing body is surely electrically connected.

The invention according to claim 3 is the invention according to claim 2, wherein the battery cap includes a cylindrical main body provided with an upper wall, and an outward flange provided at an opening end of the main body, The urging means is arranged inside the main body.
If the urging means is disposed inside the cylindrical main body as in the above configuration, the urging means is held in the main body so that the urging force is reliably applied to the battery cap and the sealing body. It will be.

According to a fourth aspect of the present invention, in the third aspect of the present invention, a contact projection is provided at a position corresponding to the outward flange in the sealing body.
With the above configuration, even if one of the lower surface of the outward flange and the upper surface of the sealing body is not flush with each other, the grounding area between the outward flange of the battery cap and the sealing body can be secured to some extent, An increase in the internal resistance of the battery can be suppressed.

The invention according to claim 5 is the invention according to claim 3 or 4, characterized in that a guide for guiding the movement of the battery cap is provided on at least a part of the periphery of the outward flange. To do.
If the guide for guiding the movement of the battery cap is provided at the periphery of the outward flange as in the above configuration, the battery cap can be prevented from being tilted and pushed down, so the outward flange of the battery cap and the sealing body An increase in the internal resistance of the battery due to a reduction in the ground contact area can be suppressed.

  According to the present invention, it is possible to suppress the occurrence of an external short circuit even when the battery is not in use, and since an insulating tube provided around the outer can is unnecessary, the manufacturing cost of the battery can be reduced, In addition, since the number of parts of the power switch of the device using the battery can be reduced, there is an excellent effect that the cost of the device can be reduced.

  Hereinafter, the content of the present invention will be described in more detail with reference to FIGS. 1 to 3, but the present invention is not limited to the following best modes, and may be appropriately changed within the scope not changing the gist thereof. Can be implemented.

  1 is a cross-sectional view of a battery in one embodiment of the present invention, FIG. 2 is an enlarged cross-sectional view of the vicinity of the sealing portion when the battery is not used, and FIG. 3 is an enlarged cross-sectional view of the vicinity of the sealing portion when the battery is in use.

  As shown in FIGS. 1 and 2, an AA size (AA size) nickel-hydrogen battery according to an example of the present invention has an outer can 1 made of iron nickel plating and having a bottomed cylindrical shape, In the outer can 1, a positive electrode in which a positive electrode active material layer mainly composed of nickel hydroxide is formed on a core made of nickel foam, and a negative electrode active material made of a hydrogen storage alloy on a core made of punching metal. A spiral electrode body (power generation element) 2 is housed which is composed of a negative electrode having a layer and a separator made of a nonwoven fabric made of polypropylene and separating these two electrodes. The negative electrode is disposed on the outermost periphery of the spiral electrode body 2, and a negative electrode current collector 22 is disposed between the lower surface of the spiral electrode body 2 and the bottom of the outer can 1. Has been placed. In addition, an electrolytic solution made of a 30% by mass potassium hydroxide (KOH) aqueous solution is injected into the outer can 1. Further, the opening of the outer can 5 is disposed between the sealing body 3, the lid 5, and the sealing body 3 and the lid 5 via an insulating insulating packing 6 made of nylon. The insulator 4 is caulked and fixed, thereby sealing the battery.

  Here, the sealing body 3 is made of iron-nickel plating and has a disk shape. As shown in FIG. 2, the sealing body 3 has a degassing at its center for exhausting the gas when the battery internal pressure rises. A hole 3a is formed. A safety valve 11 is provided at the center of the lower surface of the sealing body 3 (the surface on the spiral electrode body 2 side). The safety valve 11 includes a dish-shaped holding body 8 that is fixed to the lower surface of the sealing body 3 and has a gas vent hole 8a formed at the center thereof, a valve body 9 that closes the gas vent hole 8a, the valve body 9 and the valve body 9 The spring 10 is interposed between the sealing body 3 and presses the valve body 9 in the direction of the gas vent hole 8a. By adopting such a structure, the gas vent hole 8a is normally closed by the valve body 9 to seal the inside of the battery. On the other hand, the battery 10 resists the urging force of the spring 10 when the battery internal pressure rises. Then, the valve body 9 is lifted and discharged out of the battery through the gas vent holes 8a and 3a and a gas vent hole 13a formed in a main body 13 of the battery cap 12 described later. The holding body 8 and the positive electrode current collector 20 of the spiral electrode body 2 are electrically connected by a positive electrode tab 21 provided integrally with the positive electrode current collector 20.

  The insulator 6 is made of ring-shaped polypropylene and insulates the sealing body 3 and the lid 5. A thickness L2 of the insulator 6 is configured to be larger than a thickness L1 of an outward flange 14 of the battery cap 12 to be described later, so that the sealing body 5 and the battery cap 3 are in contact with each other in a normal state. It is preventing. In this embodiment, the thickness L2 of the insulator 6 is 2 mm.

  Further, the lid 5 is made of iron-nickel plating, and a through hole 5a is formed at the center thereof. A battery cap 12 made of iron-nickel plating having a role as a positive electrode terminal is inserted into the through hole 5a. The battery cap 12 includes a cylindrical main body 13 provided with an upper wall 13 b and an outward flange 14 provided integrally with the main body 13 at the opening end of the main body 13. The side wall (cylinder part) 13c of the main body part 13 is formed with a vent hole 13a for discharging the gas in the battery at the time of abnormality such as when the battery internal pressure rises. The outer diameter L3 of the main body 13 is configured to be smaller than the inner diameter L4 of the through hole 5a, so that the battery cap 12 can smoothly move downward (A direction in FIG. 2). . On the other hand, the outer diameter L5 of the outward flange 14 is configured to be larger than the inner diameter L4 of the through hole 5a to prevent the battery cap 12 from coming off.

  An insulating plate 16 made of polypropylene is provided on the inner side surface of the upper wall 13 a of the main body 13, and a spring 15 is interposed between the insulating plate 16 and the sealing body 3. . The biasing force of the spring 15 is such that the positive electrode terminal can be easily pushed with a finger, specifically, the force when the battery cap 12 is brought into contact with the sealing body 3 is 500 g (that is, the thickness L2 of the insulator 4 is 2 mm) Therefore, the biasing force of the device-side spring is set to about 700 g when a battery is mounted on a device (not shown) to which an AA size battery is mounted. . For this reason, when the battery is mounted on the device, the battery cap 12 moves inward of the battery (direction A in FIG. 2) against the biasing force of the spring 15, and as shown in FIG. The outward flange 14 of the battery cap 12 and the sealing body 3 electrically connected to the positive electrode are in contact with each other. As a result, the energy inside the battery can be taken out of the battery. When the battery is removed from the device, the battery cap 12 is moved outward (direction B in FIG. 3) by the urging force of the spring 15 to return to the state shown in FIG. .

  Here, the nickel-hydrogen battery having the above structure was manufactured as follows. First, a nickel foam (core body) was filled with a paste-like positive electrode active material mainly composed of nickel hydroxide, dried, and then rolled to a predetermined thickness to prepare a nickel positive electrode plate. In parallel with this, a hydrogen-absorbing alloy negative electrode plate is obtained by filling a punching metal (core body) with a paste-like negative electrode active material whose main component is a hydrogen storage alloy, drying, and rolling to a predetermined thickness. Was made.

  Next, the nickel positive electrode plate and the hydrogen storage alloy negative electrode plate thus produced were wound in a spiral shape with a separator made of a nonwoven fabric made of polypropylene, with the outermost periphery being a negative electrode plate. Electrode body 2 was produced. Next, the positive electrode current collector 20 is placed on the upper part of the spiral electrode body 2 described above (the part where the current collector portion of the positive electrode is exposed), and then a welding current is passed to thereby form the spiral electrode body 2 and the positive electrode. The current collector 20 was fixed. On the other hand, the negative electrode current collector 22 was placed on the lower part of the spiral electrode body 2 (the part where the current collecting part of the negative electrode was exposed), and both were fixed by flowing a welding current.

  Then, the bottomed cylindrical outer can 1 was prepared, the spiral electrode body 2 was inserted into the outer can 1, and the negative electrode current collector 22 and the bottom of the outer can 1 were spot welded. Thereafter, an electrolytic solution made of a 30% by weight potassium hydroxide (KOH) aqueous solution is poured into the outer can 1, and the sealing body 3 with the safety valve 11 is placed on the upper surface of the positive electrode tab 21 to perform an energization process. Thus, the sealing body 3 and the positive electrode of the spiral electrode body 2 were electrically connected.

  Finally, the ring-shaped insulator 4 is disposed on the upper portion of the sealing body 3, the insulator 16 and the spring 15 are sequentially stored in the battery cap 12, the battery cap 12 is disposed on the sealing body 3, and With the lid 5 placed on the insulator 16 so that the tip of the battery cap 12 protrudes from the through hole 5a of the lid 5, the opening end of the outer can 1 is crimped via the insulating packing 6. A nickel-hydrogen battery was manufactured by fixing the sealing body 3, the insulating packing 6, and the lid 5 to the opening end of 1.

[Other matters]
(1) In the above embodiment, as shown in FIG. 4, there is a case where the battery cap 12 is tilted and pushed down. In such a state, the ground contact area between the outward facing portion 14 of the battery cap 12 and the sealing body 3. Decreases and the internal resistance of the battery increases. Therefore, as shown in FIG. 5, by providing the guide member 30 on the outer side of the outward flange 14, it is possible to avoid the occurrence of the above inconvenience.

(2) As shown in FIG. 6, the outer diameter of the outward flange 14 of the battery cap 12 may be slightly smaller than the inner diameter of the ring-shaped insulator 4. With such a configuration, the ground contact area between the outward flange 14 of the battery cap 12 and the sealing body 3 is increased, the internal resistance of the battery is reduced, and the insulator 4 is guided by the above (1). Since the role as a member can be exhibited, it is not necessary to provide a separate guide member, and the manufacturing cost of the battery can be reduced.

(3) As described above, the battery cap 12 and the sealing body 3 are electrically connected by the contact between the lower surface of the outward flange 14 of the battery cap 12 and the upper surface of the sealing body 3. However, it may be difficult to make the lower surface of the outward flange 14 and the upper surface of the sealing body 3 flush with each other. If a battery is manufactured in such a state, the outward flange 14 and the sealing body of the battery cap 12 are produced. As a result, the internal resistance of the battery increases. Therefore, as shown in FIG. 7, if the contact protrusion 31 is provided on the upper surface of the sealing body 3, even when one of the lower surface of the outward flange 14 and the upper surface of the sealing body 3 is not flush, Since the ground contact area between the outward flange 14 of the battery cap 12 and the sealing body 3 can be secured to some extent, an increase in the internal resistance of the battery can be suppressed. The formation site of the contact protrusion 31 is not limited to the upper surface of the sealing body 3, and may be the lower surface of the outward flange 14 of the battery cap 12.

(4) In the best mode, the side wall (cylinder part) 13c of the main body 13 of the battery cap 12 and the spring 15 are in contact with each other, so that the battery cap 12 and the sealing body 3 are electrically connected when the battery is not used. There is a risk of conduction. Therefore, in order to avoid such inconvenience, as shown in FIG. 8, the insulator 16 may be disposed on the entire side wall (cylinder portion) 13 c of the main body portion 13. Further, if an insulating spring (for example, a metal spring whose surface is covered with vinyl or the like) is used as the spring 15, the above inconvenience can be avoided without disposing the insulator 16.

(5) The position of the spring 15 is not limited to the inside of the main body 13 of the battery cap 12, and may be disposed between the outward flange 14 of the battery cap 12 and the sealing plate 3. However, in this case, since a measure for preventing the spring 15 from coming off is required separately, it is desirable to dispose the spring 15 in the main body 13 of the battery cap 12. In the above-described best mode, the case of an AA size battery (in this case, the urging force of the device side spring when the battery is attached to the device is about 700 g) has been described as an example. Of course, the present invention can also be applied to a size or AAA size battery. At this time, the urging force of the device-side spring when the battery is mounted on the device is about 1000 g for the single size, about 900 g for the single size, and about 400 g for the single size. It is necessary to set the power accordingly.

(6) The elastic body is not limited to the above-described spring, and may be a stretchable resin or rubber.
(7) The battery to which the present invention can be applied is not limited to the nickel-hydrogen storage battery, but can be widely applied to other types of secondary batteries such as a nickel-cadmium storage battery and a lithium ion secondary battery. Can do. In the above-described best mode, a cylindrical battery is used, but it is needless to say that the present invention can also be applied to a square battery or the like.

  The present invention can be applied to, for example, a driving power source of a mobile information terminal such as a mobile phone, a notebook computer, and a PDA.

It is sectional drawing of the battery which concerns on the best form of this invention. FIG. 2 is an enlarged cross-sectional view of the vicinity of a sealing portion when the battery of FIG. 1 is not used. It is an expanded sectional view of the sealing part vicinity at the time of use of the battery of FIG. It is an expanded sectional view of the sealing part vicinity which shows the inconvenient state of the battery of FIG. It is an expanded sectional view of the sealing part vicinity which shows the modification of the battery of FIG. It is an expanded sectional view of the sealing part vicinity which shows the modification of the battery of FIG. It is an expanded sectional view of the sealing part vicinity which shows the modification of the battery of FIG. It is an expanded sectional view of the sealing part vicinity which shows the modification of the battery of FIG.

Explanation of symbols

1: exterior can 2: spiral electrode body 3: sealing body 12: battery cap 13: body part 14: outward flange 15: spring

Claims (5)

A power generation element having both positive and negative poles is housed in a bottomed cylindrical outer can, and this outer can is electrically connected to one of the positive and negative poles to form a terminal of one pole, and In the opening of the outer can, a sealing body electrically connected to the other of the positive and negative electrodes, and a battery cap constituting a terminal of the other pole by being electrically connected to the sealing body, However, in the battery provided in order from the inside of the battery in an insulated state from the outer can,
The battery cap and the sealing member are not electrically connected when the battery is not used, and the battery cap and the sealing member are electrically connected when the battery is used.   Between the battery cap and the sealing body, an urging means for urging the two in the direction of separating them is provided, and the urging force of the urging means is provided on a device to which the battery is attached. The battery according to claim 1, wherein the battery is configured to be smaller than an urging force of the urging means.   The battery cap includes a cylindrical main body portion provided with an upper wall and an outward flange provided at an opening end of the main body portion, and the urging means is disposed inside the main body portion. The battery according to claim 2.   The battery according to claim 3, wherein a contact protrusion is provided at a position corresponding to the outward flange in the sealing body. 5. The battery according to claim 3, wherein a guide for guiding movement of the battery cap is provided on at least a part of a peripheral edge of the outward flange.